preparation of graphene -modified lifepo cathode for li
TRANSCRIPT
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FINAL REPORT
Preparation of Graphene-Modified LiFePO4 Cathode for Li-Ion Battery
SUBMITTED TO
North Dakota Department of Commerce Renewable Energy Program
SUBMITTED BY
University of North Dakota College of Engineering and Mines
Institute for Energy Studies P.O. Box 7101
Grand Forks, ND 58202 D-U-N-S Number: 10-2280781
&
Private Sector Partner Clean Republic LLC
5515 University Ave., Grand Forks, ND58203
PRINCIPAL INVESTIGATOR
Xiaodong Hou Phone: (701) 777-6791 Fax: (701) 777-1820
Request Fund from State - $238,366 Match Fund from Clean Republic - $247,873
Total Proposed Project Cost - $486,239
Total Project Duration – 27 Months (March 1, 2018 to May 31, 2020) (24 months plus 3-month approved extension)
REPORT SUBMITTED DATE June 30, 2020
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1 Table of Contents
2 Executive summary ............................................................................................................................... 3
3 Introduction ........................................................................................................................................... 4
3.1 Background ................................................................................................................................... 4
3.2 Statement of the problem .............................................................................................................. 5
3.3 Technology description ................................................................................................................. 5
3.4 Scope of work ............................................................................................................................... 5
4 Technical Achievements ....................................................................................................................... 5
4.1 Goal and objectives ....................................................................................................................... 5
4.2 Results and discussion .................................................................................................................. 6
4.2.1 Humic Acid extraction and purification in lab-scale ............................................................ 6
4.2.2 LFP/G synthesis, characterization, electrochemical performance in lab-scale ..................... 7
4.2.3 Pilot-scale production of Humic Acid ................................................................................. 10
4.2.4 Pilot-scale production of LFP/G ......................................................................................... 11
4.2.5 Conclusion and Discussion ................................................................................................. 13
5 Commercialization progress ............................................................................................................... 13
5.1 Review of Competitive Landscape ............................................................................................. 13
5.1.1 Table 4-1. Cost/profile structure of producing one ton of LFP by the proposed technology
compared with the prices of commercial ones in the current market .................................................. 14
5.2 Market Need ................................................................................................................................ 14
5.2.1 Meet Clean Republic LLC’s own need ............................................................................... 15
5.2.2 Other potential markets ....................................................................................................... 15
5.3 Commercialization progress ....................................................................................................... 15
5.4 Other direct outcomes ................................................................................................................. 16
6 Summary of The Project Achievements ............................................................................................. 17
7 References ........................................................................................................................................... 19
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2 Executive summary
Starting from May 2015 a Grand Forks-based private company Clean Republic (CR) sponsored the
University of North Dakota (UND) Institute for Energy Studies (IES) to launch a collaborative research
effort to develop its lithium iron phosphate (LFP) cathode material for Li-ion batteries (LIBs) to overcome
a severe quality inconsistency issue with commercial LFP. Under an award from the North Dakota
Department of Commerce (Venture Grant I/II), the project team reached their goal of producing low-cost
and high consistent LFP cathodes with a specific capacity of 120-130 mAh/g (comparable to commercial
cathodes but at much less cost). The success of that project will help Clean Republic differentiate their LFP
product from its competitors in terms of quality consistency and cost. Based on the positive results of the
project, to hold the leading position in this competitive industry, in the current project our team is proposing
to further improve the technology to prepare a more advanced product - graphene-modified lithium iron
phosphate cathode materials (LFP/G) at pilot-scale (10 tons/year). LFP/G has advantages over conventional
LFP in many aspects including energy density, rate capability, cycling stability and low-temperature
performance. The target-specific capacity of the LFP/G is 150 mAh/g, another 15% improvement over our
current technology. The primary target market of the LFP/G cathode materials is Clean Republic’s own
need on its main products - ‘Dakota Lithium’ packs and ‘HillTopper’ E-bikes. The long-range goal is to
produce LFP/G at large scale and its target market is the large battery pack for energy storage to support
intermittent renewable energy generation.
The new synthetic procedure is a proprietary technology that combines the advantages of the two
mainstream procedures for LFP synthesis – the simplicity of solid-phase reaction routes and the
homogeneity of liquid-phase reaction routes. The procedure was evaluated at two stages, the lab-scale
(Phase I, grams level) and pilot-scale (Phase II, kilograms level), focusing on two key technical objectives:
high purity and batch-to-batch quality consistency. The procedure was proven at both scales with the main
technical objectives achieved: the purity of the LFP powder greater than 99%, and reached the target-
specific capacity 150 mAh/g, and the relative standard deviation of physical properties less than 15% and
electrochemical properties less than 5%.
The success of the proprietary procedure at pilot-scale paves the way to the primary commercialization goal
of the project: produce LFP that meets Clean Republic’s demand. In 2017 Clean Republic had a demand
for more than 10 tons of LFP powder. The demand has been continuously growing by 30-40% annually
since the company started in 2008 and is witnessing a sharp increase in last two years (10-fold) driven by
the quickly growing demand on the “Dakota Lithium”. As the primary commercialization goal, pilot-scale
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production of 10 tons/year can sufficiently benefit Clean Republic. Encouraged by the success of the
technology and strong commercial demand, Clean Republic is accelerating the commercialization process
of this technology. Two goals were set on Clean Republic’s board meeting early spring in 2018: 1) establish
a pilot-scale production line for LFP (10 ton/year) in one year from the end of this project, and 2) increase
the “Dakota lithium” production capacity by 10 times by the end of 2018.
3 Introduction
3.1 Background Over recent years, the demand for clean and sustainable energy has dramatically grown. Lithium ion
batteries (LIBs) are currently most likely to meet these energy storage requirements due to their high energy
densities, low weight, and good lifespan. [1] Several varieties of LIBs exist, each with unique properties that
make them suitable for different application. Table 2.1-1 lists several popular lithium ion cathode
chemistries as well as their strengths, benefits, and typical applications.
3.1.1.1 Table 2.1-1 Popular Lithium-Ion Battery Chemistries and Their Attributes. Cathode Material
Manufacturers Typical Applications
Date Commercialized
Specific Capacity
Specific Power
Safety Cycle Life
Price Comments
NMC Imara Coroporation,
LG Chem, Nissan Motor
EV’s, medical devices, industial,
E-bikes
2008 **** *** *** *** *** High specific capacity and power, good
safety and cost. Still relies on cobalt.
LMO E-One Moli Energy, Hitachi,
Samsung
Power tools, medical devices,
Ev’s
1996 *** *** *** ** *** High power, safer than LCO, but low
capacity. Often mixed with NMC
LFP Phostech Lithium Inc,
Simplipi power
Segway, power tools, energy
storage
1996 ** **** **** **** *** High power, excellent stability and lifespan,
but low specific capacity. One of the
safest Li-ions. LCO Sony, E-one
Moli Energy Mobile phones, tablets, laptops
1991 **** ** ** ** *** High specific capacity, but low power and safety.
High cost. LCA Panasonic, Saft
Groupe S.A. EV’s, medical
devices, industial 1999 **** *** ** *** ** High specific
capacity, good power and lifespan. Poor price and safety.
NMC: Lithium Nickel Manganese Cobalt Oxide, LiNixMnyCozO2; LMO: LiMn2O4; LFP, LiFePO4; LCO: LiCO2; NCA: LiNiCoAlO2.
Of all cathode materials, LiFePO4 (LFP) is specifically interesting because of its intrinsic crystal structure
(orthorhombic olivine) and chemical stability that leads to excellent safety and superior long cycle life.
Moreover, the low cost, environmentally benign and abundant sources of raw materials Fe and PO43-
moieties facilitate its large-scale applications. However, the poor discharge/recharge rate capability due to
the slow diffusivity (10-14 to 10-16 cm2s-1) of the 1D Li+ transportation in the olivine structural of LFP with
poor electronic conductivity significantly limits its applications [2]. Since the pioneering work of John
Goodenough and coworkers [3,4], a great number of projects have been conducted to investigate the synthesis,
structure, defects, and physical, chemical and electrochemical properties of LFP. Various approaches, such
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as size reduction, conductive surface coating (i.e., carbon coating) and doping, etc., have greatly improved
the performance of LFP [5, 7].
3.2 Statement of the problem Since its discovery in 2004, graphene has been considered an ideal material to make composite electrodes
to improve the overall performance of LFP because of its high charge carrier mobility (200,000 cm2V-1s-1),
high theoretical surface area (2630 m2g-1), a broad electrochemical window, and other remarkable properties.
Recent reports have demonstrated that graphene-modified LFP cathode (LFP/G)-based LIBs displayed
remarkably improved electron transportation, which is quite significant to achieve high energy density,
good cycling stability, rate capability, and low-temperature performance. However, the most existing
research on the preparation of LFP/G requires the synthesis of graphene in advance, which severely inhibits
its practical applications, as cost-effective production of graphene at large scale is still a big challenge.
3.3 Technology description To solve this problem, we proposed to develop a low-cost synthetic procedure to prepare LFP/G for LIBs.
Specifically, a two-step procedure is proposed: 1) humic acid is extracted and purified from low-rank ND
coal or leonardite and 2) the extracted humic acid is then mixed with a Li source and FePO4 to in situ
prepare LFP/G via a novel modified carbothermal reduction reaction that has been well-established from
previous development efforts by UND IES and Clean Republic. The detailed description of the proposed
technology is confidential. Such information shall be used or disclosed only for the review and evaluation
purpose.
3.4 Scope of work Task 1 involves humic acid extraction and purification procedure optimization. Task 2 involves LFP/G
synthetic procedure optimization. Task 3 focuses on the characterization of LFP powder and
electrochemical performance testing of the LFP-based LIBs. Task 4 involves the pilot-scale production
testing.
4 Technical Achievements
4.1 Goal and objectives The overall goal of the proposed work is to develop a low-cost, reproducible, and environmentally benign
synthetic procedure for LFP/G to be used as cathode materials in LIBs at pilot-scale (10 tons/year). The
ultimate goal is to produce the LFP/G at large scale and its target market is the large battery pack for energy
storage to support renewable energy generation. The anticipated specific capacity of 150 mAh/g represents
a 15% improvement over current technology. Rate capability, low temperature and cycling stability of the
LFP/G are also expected to be improved simultaneously. Specific objectives include:
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Optimization of humic acid extraction procedure.
Optimization of LFP/G synthetic procedure.
Characterization, Electrochemical Performance Testing of LFP/G Cathode.
Pilot-scale production and testing.
4.2 Results and discussion Details of the procedure and associated materials are proprietary. The methods of characterization and
measurement were included in the original proposal. This final report summarizes the results generated by
the optimized procedure.
4.2.1 Humic Acid extraction and purification in lab-scale
The optimization of humic acid extraction and purification procedure was conducted on North Dakota raw
leonardite (kindly provided by Leonardite Production). The selected extraction solutions (alkaline solutions
and organic solvents) and extraction conditions were optimized to finalize the optimal procedure. The
evaluation criteria include humic acid yield, purity, and iron content. The results are shown in Table 3.2.1-
1. The basic extraction procedure shows better performance with 45.3% of yield, 96.9% of purity and 0.96%
iron content than organic solvents extraction.
4.2.1.1 Table 3.2.1-1 The Humic Acid yield, purity, and iron content after the extraction procedure.
Yield, % Purity, % Fe Content, % Lignite / 90.7 2.52
Basic Extraction 45.3 96.9 0.96 Solvent Extraction 32.7 97.7 1.24
Additional humic acid purification steps are required to reduce impurities to a level qualified for high-tech
applications such as battery electrode materials. Typically, most of the salts can be removed by rinsing the
HA with de-ionized water for few times, and the wash step also reduces ash content. Strong organic-metallic
complexes can be disrupted and removed using a strong chelating agent. The results of humic acid
purification process are shown in Table 3.2.1-2.
4.2.1.2 Table 3.2.1-2 Iron Content and HA Purity after further purification. Sample Approach Iron, wt. % Purity of HA, % HA-0 Extracted raw humic acid 0.96 96.9 HA-1 Chelating agent 1 0.09 97.9 HA-2 Chelating agent 2 0.10 97.6
Washing extracted HA with de-ionized water has proven effective to remove residual salts and reduce
chlorine content from 2.29% to less than 0.20% for one sample. A strong chelating agent is necessary to
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remove iron and other metal ions from HA and was found to reduce iron by almost 90%. The optimized
extraction procedure and the purification techniques developed in this section could produce high purity of
HA for LIB applications.
4.2.2 LFP/G synthesis, characterization, electrochemical performance in lab-scale
LFP/G synthetical methods were developed jointly between CR and the University of North Dakota.
This proprietary process incorporating HA into LFP ensures excellent crystal purity and molecular level
mixing. Two typical examples of LFP/G samples were marked as LFP/G A and LFP/G B with the difference
in the preparation procedure: for sample A, humic acid was directly mixed with the precursors, while for
sample B, humic acid is dissolved completely prior to mix with precursors. Figure 3.2.2-1 shows XRD
profiles of LFP/G A, LFP/G B, and LFP reference samples and a close-up view of this (002) graphitized
carbon peak. The identical profiles indicate the sample synthesized at lab-scale has the same crystal
structure as its lab-scale counterpart. The complete overlapping of the measured data of LFP/G A and
LFP/G B with the theoretical data (green) indicates the high purity of the expected ovine crystal structure
as Triphylite. The purity of our LFP/C is greater than 99.5% by Rietveld Analysis. The presence of (002)
graphitized carbon peak confirms that HA is forming graphitized carbon at the temperatures used for
thermal treatment and LFP/G synthesis.
4.2.2.1 Figure 3.2.2-1 XRD Profiles of LFP/G A, LFP/G B, and LFP Reference Samples. Profiles are offset vertically for clarity.
Figure 3.2.2-2 displays SEM images of LFP/G A and B samples at 100 × and 5000 × magnifications. For
sample A, although the LFP and graphitized HA particles were interacting as shown in figure 3.2.2-2 (a, b),
they were not homogenously mixed in a manner that would facilitate enhanced electrochemical
performance. On the contrary, sample B was homogenous, particles appeared fairly uniform in size, with
no obvious irregularities or anomalies.
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4.2.2.2 Figure 3.2.2-2 SEM Images of LFP/G A and B samples at different Magnification.
LFP/G A (a, b), LFP/g B (c, d).
Raman analysis was used to inspect samples for graphene-like carbon and determine the ratio of ordered
amorphous carbon. Figure 7.3.3-1 compares Raman spectra for LFP/G A, LFP/G B, and LFP reference
samples. The peak at 1350 cm-1 corresponds to the carbon D-band, representing disordered carbon, and the
peak at 1580 cm-1 is the G-band for ordered, graphene-like carbon. The ratio of peak intensities, ID/IG, is a
useful metric for gauging the ratio of amorphous carbon to ordered carbon. Sample LFP/G A had an ID/IG
ratio of 0.53, which is lower than that of LFP/G B (ID/IG ratio of 0.66). It indicates that the LFP/G samples
had a much higher degree of ordered carbon as a result of using HA as the carbon source.
a
b
c d
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4.2.2.3 Figure 3.2.2-3 Raman Spectra of LFP/G and LFP Reference Samples. LFP reference profile is solid red line, LFP/G A profile is black dashed line, and LFP/G B profile is blue dashed
line.
Carbon contents of the LFP/G and LFP reference samples are listed below in Table 3.2.2-1. The LFP/G B
sample had a more favorable carbon content, as a lower carbon content corresponds to a higher activate
material content and higher energy density.
4.2.2.4 Table 3.2.2-1 Carbon Contents for LFP/G and Reference Samples. Sample Carbon Content, %
LFP Reference Sample 6.91 LFP/G A 10.49 LFP/G B 4.40
The specific capacity at a 0.1C charge/discharge rate for coin cells prepared with LFP/G and LFP reference
samples are shown below in Table 3.2.2-2. The specific capacity of the reference sample was approximately
118 mAh/g and sample LFP/G A was about 125 mAh/g. Sample LFP/G B had an elevated specific capacity
of roughly 145 mAh/g. This increase in capacity is due to the synthesis procedure that allows for molecular
level mixing and better LFP-HA interaction, and a reduced carbon content. HA was mixed with LFP
particles much more homogenously in sample LFP/G B than in LFP/G A. The fact that the flaky and carbon-
dense regions of graphitized HA observed under SEM in sample LFP/G A were not observed in sample
LFP/G B also supports the claim above.
4.2.2.5 Table 3.2.2-2 Specific capacity of LFP/G and Reference Samples. Sample Specific capacity, mAh/g
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LFP Reference Sample 118 LFP/G A 125 LFP/G B 145
LFP/G B coin cells had the highest specific capacity at 145 mAh/g at 0.1C as well as the best capacity
retention during high-rate testing that ascribes to better interaction between the LFP material and the
graphitized HA as a result of the synthesis procedure. These results indicate that leonardite-derived HA is
an excellent graphene-precursor for LIB electrode materials.
4.2.3 Pilot-scale production of Humic Acid
To investigate the feasibility of upscaling our HA production technology, a pilot-scale test was conducted
by industrial filter press (M.W. WATERMARK™, as shown in figure 3.2.3-1). Notice we use ND lignite
instead of leonardite as feedstock in the pilot scale, as the filter press has a preferable particle size range of
the residuals to achieve the best liquid-solid separation. To cope with the change on the raw materials, some
minor modifications of operation conditions were applied to the established lab-scale procedure. However,
because of the high similarity of leonardite and lignite, we expect the results and finding below will apply
to leonardite as well.
4.2.3.1 Figure 3.2.3-1 An industrial filter press was used for pilot-scale Humic Acid production
Table 3.2.3-1 shows a comparison of ash and iron content of raw humic acid and pure humic acid. Table
3.2.3-2 displays the elemental composition results of raw humic acid and pure humic acid by XRF.
Surprisingly, unlike the time-consuming purification process in a lab-scale test, the optimized procedure
for pilot-scale HA purification is quite effective on removing ash and most of the salts, which can greatly
increase the HA production efficiency. We attribute this difference to the use of filter press as the major
separation device, though the difference in raw materials may be a minor contributor.
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4.2.3.2 Table 3.2.3-1 A comparison of Raw HA and Pure HA. sample Ash, % Iron, %
Raw HA 15.58 2.11 Pure HA 1.41 0.13
4.2.3.3 Table 3.2.3-2 Elemental Compositions of Raw and Pure HA. Values are in mass percent. Sample Na Mg Al Si P S Cl K Ca Ti Fe HA
Raw HA 2.35 0.03 1.49 2.17 0.08 1.46 1.27 0.17 0.11 0.08 2.11 88.6 Pure HA 0 0.01 0.20 0.28 0.05 1.73 0.02 0.03 0.01 0.06 0.13 97.4
In short, in this section a new process was developed to purify the raw lignite with high production
efficiency, showing a great potential for industrial application. Notice, a lab centrifuge was used to separate
the ash from the raw HA solution due to the equipment limitation. For industrial production, liquid-solid
separation can be easily achieved by a semi-continuous centrifuge.
4.2.4 Pilot-scale production of LFP/G
To fabricate the full cylinder cell series like 18650 or 26650, over 1 kg of LFP/G C was produced during
the final pilot-scale production. From the previous section, LFP/G B coin cells shown the highest specific
capacity at 145 mAh/g at 0.1C as well as the best capacity retention during high-rate testing. In this section,
similar cathode material was synthesized and to be tested in a full cylinder cell. In LFP/G precursor
production, a spray dryer was confirmed as a highly efficient continuous drying equipment as well as the
combination of a mixer and a jet mill in the original proposal. This change was to cope with a major
equipment (jet mill) failure and the significant delay on the repair service due to the COVID-19 pandemic.
Nevertheless, the jet mill that has been restored recently has been proven an effective way to grinding the
final products, as we tested on several scale-up experiments. The results were summarized below.
XRD analysis initially verifies the purity of the LFP crystal structure. Figure 3.2.4-1 shown below displays
XRD profiles of LFP/G lab-scale (R62-1) and pilot-scale (P9), LFP/G C samples. The green pattern peaks
are consistent with a typical LFP pattern, exhibiting an olivine crystal structure (Pmnb space group). The
identical profiles indicate all the samples synthesized at lab-scale and pilot-scale have the same crystal
structure. The complete overlapping of the measured data (red) of P9 with the theoretical data (green)
suggests the high purity of the expected ovine crystal structure as Triphylite. The purity of our LFP/G is
greater than 99.5% by Rietveld Analysis. An additional peak located at approximately 26.5° at 2θ
corresponds to the (002) peak of graphitized carbon.
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4.2.4.1 Figure 3.2.4-1 XRD Profiles of LFP/G lab-scale (R62-1) and pilot-scale (P9), LFP/G C. A typical olivine-structured LFP pattern is on the bottom in green.
Figure 3.2.4-2 displays the SEM images of LFP/G C sample at 2,000× and 5,000× magnifications, the
sample was homogenous, and no carbon-rich regions were observed. Due to the nature of the LFP/G C
synthesis procedure, HA can be dissolved into solution and interact with LFP precursors at a molecular
level. This leads to a thin, even coating of graphitized carbon on the LFP particles rather than the large
carbon agglomerations observed in the sample LFP/G A. Secondary LFP particles in the sample LFP/G C
also did not appear as large as those in the sample LFP/G A. It is possible that HA is acting as a surfactant,
preventing clumping and the agglomeration of LFP precursors during mixing. Closer inspection revealed
nano-sized particles with rounded edges. Also, the particles appeared fairly uniform in size, with no obvious
irregularities or anomalies.
4.2.4.2 Figure 3.2.4-2 SEM Image of LFP/G C.
The specific capacities of two samples at a 0.05C charge/discharge rate for coin cells prepared with LFP/G
are shown below in Table 3.2.4-1. Charging profiles begin at a capacity of zero and approximately 2.5 volts
and the capacity increases with voltage. Discharge profiles begin at a zero capacity around 4.2 volts, and
Meas. data:P9Meas. data:R62-1
2-theta (deg)
Inte
nsity
(cou
nts)
10 20 30 40 50 60 0
10000
20000
30000
40000
50000
60000
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the capacity increases as voltage drops. Specific capacity of the samples can be estimated by reading the
final capacity of the discharge curve at the lower voltage cut-off point of 2.5 volts. The specific capacity of
the LFP/G C sample was approximately 150 mAh/g at a charge/discharge rate of 0.05C.
4.2.4.3 Table 3.2.4-1 Specific capacity of LFP/G and Reference Samples. Sample Specific capacity, mAh/g
LFP/G P9 146 LFP/G C - 1 151 LFP/G C - 2 150
LFP/G C coin cells shows a specific capacity at around 150 mAh/g at 0.05C, suggesting the better bonding
between the LFP material and the graphitized HA. Coin cells were prepared with active materials
synthesized using HA have benefited from enhanced capacity and performance. These results indicate that
Humic acid produced by our pilot-scale test has high purity and can be used as a graphene precursor for
making LIB electrode materials.
4.2.5 Conclusion and Discussion
In conclusion, an optimized procedure for extracting and purifying humic acid from ND leonardite/lignite
was developed at both a lab-scale and a pilot-scale. The procedure showed a great potential application in
producing high purity of humic acid at an industrial scale. The as-prepared humic acid modified LFP
cathode material shows crystal purity >99.5% evidenced by XRD results. And the Raman Spectra
confirmed the carbon from humic acid is highly ordered graphitic carbon compared with the reference
carbon precursor. Compared with the reference materials, the electrochemical performance of the coin cells
(CR2032) prepared with the as-prepared humic acid modified LFP cathode material is significantly
enhanced: the LFP/G samples meet the anticipant specific capacity at 150 mAh/g, a 15% increase over the
commercial ones. Due to the Covid-19 pandemic, a minor task is to be completed: a kilogram-batch LFP/G
sample needs send to a cylinder cell producer to assemble large cylindric cell to further confirm the
electrochemical performance. We will update the final report when the test results are available.
5 Commercialization progress
5.1 Review of Competitive Landscape There are two types of competitive technology: conventional solid-phase reaction (CRT) routes and newly
emerging liquid-phase routes. The former is the mainstream route in the current market, the leading LFP
suppliers in the world such as former A123, Valence, Sony and Phostech are all using this route in industrial
applications, but the cost of this route is high. The liquid phase method is relatively cheap, but the reliability
and consistency of products are not as good as CRT, especially in terms of cycle life.
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As detailed in Table 4-1, the estimated cost of our LFP is about $10,610 per ton, in contrast to the current
market price from $14,000 made in China to $30, 000 made in US. Cathode material LFP represents 35%
of the battery cells’ cost in total. By using the self-produced LFP, Clean Republic LLC can save about 17%
of the cost of its current LIBs, which is equivalent to at least a 19% cost decrease of its final battery packs,
such as its E-bike, ice fishing, and Dakota Lithium batteries. Given a 19% cost saving on production, Clean
Republic can significantly strengthen its competitiveness and expand its share in the lithium-ion battery
market in a short period. That is the main driving force for Clean Republic to sponsor the initiation and
continuous development of the proposed technology.
5.1.1 Table 4-1. Cost/profile structure of producing one ton of LFP by the proposed
technology compared with the prices of commercial ones in the current market Cost (per ton) Our LFP Projected market
price Made-in-China price
Made-in-US price
Fe & P sources $4,400 Li source $3,400 Other additives
$2,270
Labor Energy overhead $540 Total cost $10,610 Market price $18,000 $14,000 $30, 000 Profit $7,390 $3,390 $19,390
5.2 Market Need According to ‘Lithium Iron Phosphate Batteries Market – Global Forecast to 2024’, a market study report
published by MarketsandMarkets, the global lithium iron phosphate battery market will grow impressively
at more than 27% during 2019-2024 [8]. The LFP batteries market is projected to reach USD 10.6 billion by
2024 from an estimated USD 8.3 billion in 2019, at a CAGR of 5.0% during the forecast period. This
growth is attributed to the increasing focus on electric and hybrid electric vehicles and high demand for
energy storage applications. Meanwhile, global production capacity is far from meeting the growing market
demand. Traditional LFP manufacturers mainly include the U.S.-based A123, Valence and Canada-based
Phostech, which hold slightly dated but mature mass production technology and supply first-grade quality
products. However, the total production capacity of Valence, Phostech and A123 is only about 1,000 tons
annually. In short, there is a huge gap between the demand and supply of LFP, especially in the sector of
first-grade quality materials in North America and worldwide.
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5.2.1 Meet Clean Republic LLC’s own need
The primary goal of the proposed project is to develop LFP that meets Clean Republic’s own need for E-
bikes and large power tools such as ice augers and electric mowers. Clean Republic has over ten years of
experience in the entire supply chain of lithium-ion batteries markets. Its own retail channels themselves
already created a demand for over 10 tons of LFP powder in 2017, and that demand has been growing by
20-30%/year since the company started in 2008. All their supply chains require the high-quality LFP
powder materials described in this proposal. Though exact sales figures are confidential, Clean Republic
already supplies tens of thousands of custom battery packs to this market. Now it is entirely possible
material could be manufactured, and their economic value retained, in Grand Forks, North Dakota.
5.2.2 Other potential markets
Besides Clean Republic’s own need, there are other huge potential markets. 1) EV and HEVs. A123 Systems,
BYD, and Electric Vehicle Power System Technology have been some prominent vendors in the market.
Accounting for a total market share of about 62%, the EVs and HEVs segment dominated the market of
LFP during 2015 [9]. 2) Energy storage. The application of LFP batteries in energy storage photovoltaic and
communication batteries is on the rise, reflecting a huge space for development. Due to their long lifetime,
cycle time and safety, LFP batteries come as the most preferred choice not only of alternative energy storage
systems, but of large grid systems in load-leveling and central back-up as well. In the USA, there were 66
electric storage projects, 24,072 kwh capacity in total, announced in 2015 to May 2016, which are to utilize
LFP batteries [10]. Those announced ‘load-leveling’ projects alone raised the demand by 192 tons of LFP
cathode material currently in the United States. Those projects indicate that energy storage systems are
generating huge demand for LFP battery products domestically and globally.
5.3 Commercialization progress
Clean Republic had made a detailed commercialization plan in the original proposal. As the project
progresses, some changes were made to cope with the internal and external environment. A brief summary
of the commercialization progress and changes is outlined as follows:
1. A 1.6 million USD from a private Sweden group was invested into Clean Republic on January
2018. The goal of this investment is to speed up the development of LFP powder and promote
“Dakota Lithium” battery pack.
2. Plans to build the pilot plant. Clean Republic has initialized a warehouse expansion plan in early
January 2018. The plan is to seek a workspace of minimum 5,000 square feet with optional
capability up to 20,000 square feet to house the LFP powder production line and the battery pack
assembly lines. The first option considered is to expand the current warehouse, owned by Tom
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Kenville. This option was already ruled out, as concerning of dusty environment, lack of super
three-phase power and limited space for expansion further. A second option that has ever been
seriously considered is to purchase one of the three facilities selling by the Minnkota Power Co. at
1822 State Mill Road, Grand Forks, ND58203. The economic development department of Grand
Forks coordinated the negotiation and the Grand Forks City offers a low-interest loan to this
transaction to encourage this purchase. Clean Republic’s board of directors has agreed to accept
the asking price of the target facility. Unfortunately, right before the settle down of the purchase
contract, an unexpected competitor North Dakota Mill and Elevator (the former across-the-street
neighbor of Minnkota Power) intercepts this transaction with an irresistible offer of buying all the
three facilities in a bundle. Eventually, CR purchased a five-acre land in the northwest of Grand
Forks and planned to build a new factory, which has been delayed because of the challenges below.
3. Delayed plan by external and internal challenges. In the past two years, Clean Republic was facing
several major challenges that slow down its commercialization of this project. 1) the major
competitors significantly reduced the products price to snatch market shares. Because of that, CR
has experienced significant financial difficulty in 2019. 2) To cope with the challenge, Clean
Republic adjusted its strategical plan and reorganized its directorial board including hiring a new
CEO in the fall of 2019. It takes about half year for the operation/function of CR to cope with the
transition. Despite COVID-19 pandemic, the first half year of 2020 has witnessed the positive
outcomes of this transition. The sale of CR’s trademarked “Dakota Lithium” has increased three-
four times, compared with the same period in the 2019.
4. Re-activation of the commercialization plan. Currently CR is under negotiation with two partners.
1) An Ohio-based company show very strong interest in partnering with CR on the LFP power and
associated battery package production. 2) The same Sweden group is considering a second-round
investment to accelerate the commercialization of the project.
5. UND IES and Clean Republic are working with UND’s Corporate Engagement and
Commercialization Office (CE&C) on patent application to protect this proprietary technology. An
IP Invention Disclosure form has been submitted to the CE&C office, UND and Clean Republic
have made an agreement on the ownership and licenseship of this intellectual property.
5.4 Other direct outcomes 1. Attract External Funding. The success of this project significantly builds up IES’s capability and
experience in lithium-ion-battery research, which rewards with a series of external and internal grants
and contracts as follow:
• A total award $259, 769 by Micropower New Energy Co. Ltd. to project titled “The Preparation
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of a High Capacity Graphene Modified Graphite /SiOx Anode Electrode for Mic-Power’ Button
Batteries” with period covered: 7/1/2020-10/31/2021.
• A total award $369,581 by DOE UCFER program to project titled “Porous Silicon/Lignite-Derived
Graphene Composite Anodes for Lithium-Ion Batteries” with period covered: 11/1/19 – 4/30/20.
• A total award $10,000 by ND EPSCoR program to project titled “Chromium Chalcogenides for
Li+ Battery Application” with period covered: 1/1/20-6/30/20.
• A total award $10,000 by ND EPSCoR program to project titled “Freestanding Lignite-derived
Graphene-based Foam Anode for Lithium ion Battery” with period covered: 1/1/20-6/30/20.
• A total awarded $140, 000 by UND VPR postdoc program to project titled “Lignite-Derived
Graphene/Si Nanocomposite Anode for Li-ion Battery “with period covered: 7/1/19-6/30/21.
• A total awarded $500,229 (match fund $252,000 included) by NDIC Research ND program to
project titled “New Battery Charing Technology” with period covered: 1/1/20-12/31/20.
• A total awarded $30,000 (match fund $15,000 included) by NDIC APUC program to project titled
“Advanced Integrated Solar-LFP Battery Powered Water Pump System for Remote Farm fields”
with period covered: 5/1/18-4/30/19.
2. This project created many opportunities for education and research. A university-company
collaborative research project provides the opportunity not only to educate the battery and energy
experts in a university, but also offer them the intern positions in a real business. On the one hand,
Clean Republic has hired four students working on its company as interns; on the other hand, the battery
research program at UND IES has been quickly growing benefited from this seeding fund. Up to date
IES has trained three graduates, one postdoc, three undergraduates and four visiting scholars on lithium-
ion-battery.
3. This project is promoting innovation and new product development in regional businesses. The
production of LFP cathode material, and associated battery packs made in North Dakota, will promote
the design and development of innovative products by regional businesses, IES has been frequently
contacted by local companies on the discussion of potential R&D collaboration in Lithium-ion-battery
relevant technologies/products. For example, Jemco Power Saver has been working with Clean
Republic and IES to develop a kind of battery-powered drain pump for agriculture irritation and animal
drinking. This project was funded $15,000 by Agricultural Products Utilization Commission (APUC).
6 Summary of The Project Achievements
This section is to summarize the project achievements and evaluate the six deliverables “point-by-point”
against the “Standards of Success” in the original proposal/contract.
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1) Development of the procedure that can produce high-purity (>99%) and metal-free humic acid
from Leonardite. A low-cost procedure for extracting and purifying humic acid from ND leonardite
was developed, and the humic acid shows high purity, low ash content (~1%), and low metallic
impurity.
2) Synthesis of high crystalline purity (>99%) LFP/G with graphene evenly distributed on the surface
of LFP particles. High crystalline purity (>99.5%) of LFP/G was successfully synthesized using
the leonardite-derived humic acid as feedstock and the formation and even distribution of graphene
coating on the surface of LFP particles was confirmed.
3) 15% specific capacity (150 mAh/g) improvement over commercial products (120–125 mAh/g) and
better cycle life. The lab-scale LFP/G cathode materials tested on coin-type cells show specific
capacities about 150-151 mAh/g, a 15% improvement over commercial products. The pilot-scale
materials show no obvious degradation on the specific capacity (146 mAh/g).
4) The production cost of LFP/G lowered by 60% compared with methods involving adding external
graphene into LFP. Based on the production yield of humic acid from raw leonardite and the humic
acid feeding ratio, our pilot-scale LFP/G testing results show the estimated cost for producing 100
kg of humic acid for a ton of LFP/G is about $500. Therefore, the cost of humic acid only occupies
about 5% of the total cost of LFP/G, which is not significant compared with the other two precursors
FePO4 and Li source. The estimated price of our LFP/G is $11,164 in contrast to $36,340 by adding
external graphene into LFP, with only 0.5% usage of graphene, which stands for a 69% of cost
reduction.
5) Ability to successfully demonstrate pilot scale production (up to 30 kg/day). The extraction and
purification of humic acid and the production of LFP/G were both tested at a pilot-scale (kilogram-
level). Our current pilot-scale facility can produce about 1-2 kg of pure humic acid per batch and a
maximum 5 kg of LFP/G per batch. The production capacity will be up to 20 kg/day if a fully
integrated continuous mode were developed or multiple production shifts were applied. Most
important, the battery performance of the LFP/G by pilot-scale is similar to the one by lab-scale,
which confirms the scalability of the developed synthetic procedure.
6) 20 new jobs within Clean Republic to expand its current product line and 30 new jobs for the
production and sale of the new cathode material by 2023. In spite of the significantly delayed
commercialization plan by several major external and internal changes, Clean Republic is still
making efforts to move the project towards commercialization.
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7 References
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[4] Padhi, A. K.; Nanjundaswamy, K. S.; Masquelier, C.; Okada, S.; Goodenough, J. B., Effect of structure
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[5] Bi, Z.; Zhang, X.; He, W.; Min, D.; Zhang, W., Recent advances in LiFePO4 nanoparticles with different
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[ 8 ] MarketsandMarkets, Lithium Iron Phosphate Batteries Market by Power Capacity, Industry,
Application, Region - Global Forecast to 2024, OCT 2019.
[9] Department of Energy, Office of Electricity Delivery and Energy Reliability DOE Global Energy
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